It is standard to secure a ski boot to a ski by means of one or more clamps that allow the boot to be pulled from the ski either when the user wants to remove the skis or in an accident to prevent injury to the user. In a standard system separate toe and heel clamps are used, each provided with a hydraulic and/or spring-loaded release mechanism.
French patent 7,303,036 of Salomon describes such an arrangement wherein the base parts of these clamps, that is the parts that do not move on the ski, are displaceable longitudinally of the ski. Thus it is not only possible to adjust the spacing between the clamps to accommodate boots of different sizes, but it is also possible to center the boot on locations fore or aft of the normal central location, in order to vary the performance of the ski.
Another system described in U.S. Pat. No. 4,141,570 supports the boot clamps on a plate that can be moved along three orthogonal axes extending longitudinally of the ski, transversely of the ski and perpendicular to its upper surface, and transversely of the ski and parallel to its upper surface. Such a system is a refinement on the arrangement allowing the boot to be moved longitudinally and is useful for adapting the bindings to different skiers.
At best such arrangements have the disadvantage that they cannot allow the binding to be fitted to the particular skier as well as to the type of ski being used, the type of snow being skied on, and the type of skiing.
More particularly a ski has a pair of edges typically formed by metal strips that are intended to bite into the snow. The shape of these edges determines the width of the ski at the tip or shovel, at the boot, and at the rear end. These shapes determine the stiffness of the ski along its length, how the ski reacts with the snow, and, in general, the overall performance of the ski. For instance when the ski is relatively narrow at the boot it is possible for the user to put more effort to work at the edges.
Thus for a normal amount of work the transverse lever arm formed by the ski is smallest when the ski is narrow at the boot. As a result it is easier for the skier to angle the ski and the ski is more lively and sensitive. On the other hand a ski that is wide at the boot will grip the snow better at its front end and, due to its curved edges, will tend to cut into the snow. Since the center of the tangential pressures is further forward the ski has a tendency to stay on drag at its rear end. As a result snowplow-type turns are easy while parallel turns are more difficult.
In French patent 954,679 a ski has edges formed as symmetrical circular arcs while in French patent 8,502,048 they are arcs, but not arranged symmetrically with respect to the ski centerline. French patent 8,113,302 has edges that diverge rearward and Austrian patent 372,860 describes ski edges that are wholly asymmetrical from the front end to the rear end of the ski. U.S. Pat. Nos. 4,688,821 and 4,700,967 describe skis where the inner edge has a relatively small radius of curvature whereas the outer edge is substantially straight so that the boot must be mounted offcenter.
Clearly no one system is capable of securing the boot of a specific skier in just the right position, taking into account his or her particular abilities, the characteristics of the skis, the type of skiing, and the type of snow. And nothing now known allows the set position of the binding to be changed without removing the ski and working on it in a shop.